Wednesday, 26 April 2017

Keep alive

I haven't blogged for a while but to assure you that I am still here and want to keep the blog alive, here is a short posting.
I am speaking at the Shefford radio club tomorrow (27th April). My subject is an update on the talk I gave at the 2016 RSGB Convention. The Secret Life of the Transverter. Unlike that talk, that was very general to fit in with the general theme of the Convention, tomorrow's talk is centred on 144MHz transverters.
I am giving a short talk on the same subject at the 2017 Dayton Hamvention, so this is a chance to run through some of the Dayton VHF Forum material, albeit the Dayton talk is MUCH shorter!

de Sam

Monday, 20 February 2017


I haven't used my TS2000x for some time. Today I reconnected it to the 70cm yagi mentioned previously. I had forgotten why I really like the TS2000. Although I have both a K3 and a IC7300 (as well as an FT817) the TS2000 is still the easiest to use, even though it doesn't have a built in spectrum display and at present I can only connect to the 10.695MHz IF with my SDR-IQ for a very restricted 30kHz span display and waterfall. Even so this has proven quite adequate for digital modes.
I've also connected my spare SignaLink sound card unit for audio input for digital modes.
The TS2000 is quite deaf on 70m, but I plan to connect a PGA432 preamp through a 12v transfer relay to improve sensitivity. If I can be bothered, with the low level of 70cm activity, I will move the preamp to masthead in due course. 0.8dB system noise figure is far better than 6 or 7dB!
Maybe conditions will improve and I'll get to work a few stations outside the county........


Saturday, 18 February 2017


I thought I might put my 70cm yagi back on the mast. It's a 21 element Wimo and did me good  service for some years.
I want to see what 70cm is like now. It may have become a lot noisier than 4 or 5 years ago when I last had 70cm 'DX' capability. 
Ideally I want to build a new 70cm transverter, but before expending (more) time on the development of a transverter I though it might be better to just connect up my TS2000 again, but with a PGA432 preamp to lower the noise figure to something a bit better than the TS2000 can achieve!
I have a reel of M&P 15mm flexible coax and that ought to allow me to mount the preamp in the shack, initially, and yet still achieve a reasonable system NF.
I also have a 500W SSPA for the band, so that ought to help any DX hear me. However, driven by the TS2000 it is limited to 350W max out or 200W for a good IMD due to the poor TS2000 TX IMD. The SSPA was originally designed as a TV transponder amplifier. 


Friday, 17 February 2017


It has now been a little over a week since Dave passed away. It seems it was a massive heart attack that took him from his family and friends. Dave was apparently fit and enjoyed his Scottish country dancing as his main activity. Indeed, he was dancing the evening before his attack.
It was only a few weeks ago that Dave went down to London to pick up his new kilt in the family tartan.
He got to wear it a few times.

The raw feelings I had when I heard about Dave have now subsided a little, but even so, until his funeral next month it will be hard to think about much else. I already miss our little chats about our products and how best to market them. Dave was just getting into his stride with HUPRF. For now the company has suspended trading, pending a decision on its future.

I have no doubt that some of the product lines will continue, but there is no guarantee as to what. I'd like to see the DG8 continue and maybe even employing the new low noise device now being used in the Anglian transverter.


Wednesday, 8 February 2017

Some Anglian updates

Before Christmas I asked SM5BSZ if he would like to do a set of confirmation measurements on one of my Anglian 3 transverters. Leif quickly identified a shortcoming of the main MMIC I had used in the Anglian 3. After some toing and froing it became apparent that a second source SPF5043 was superior to the original RFMD ones. I am currently trying the replacement devices and some other changes that Leif suggested and if all goes well, and there are no adverse affects on the Anglian's performance, I will upgrade the kit to include the new devices and the other changes. The initial indications are that the performance will show a worthwhile improvement in noise (not a change in noise figure) performance. You should look at Leif's Youtube channel videos for more information.

For the moment I have run out of kits and before releasing the new version (possibly the Anglian 3L) I will need to restock with the changed parts. 

Can I emphasise that the existing Anglian 3 is an excellent performer, with many users, and it has been used in a fair number of 2m contests to good effect. There is no point in upgrading unless you are after even better performance......

The changes, if adopted, will make the Anglian 3 even better. For the cost of the transverter kit it would be difficult to find anything that performs as well.